1. Field of the Invention
The present invention relates to a governor device installed in a diesel engine, and more specifically to a governor device provided with a mechanical governor or a pneumatic governor.
2. Prior Art
Generally, the aforementioned governor device is constructed as follows. A control rack of a fuel injection pump is adapted to be operatively controlled through a governor lever in accordance with a balance between a resilient force exerted to a fuel increasing side by a governor spring and a governor force exerted to a fuel decreasing side by an actuation member such as a governor weight and the like. Thereby, though a load of a diesel engine changes, an engine revolution speed can be maintained at a predetermined value.
As such governor device, there has been known the one provided with two levers as a governor lever as disclosed in Japanese Utility Model Laid Open Publication No. 1987-82345. This prior art was filed by an assignee of the present invention and is constructed as follows.
That is, the governor lever comprises a fork lever to be engaged with the control rack and a spring lever actuated by a tension force of the governor spring. The spring lever is adapted to be received by a fuel limiting pin at the full load position, and the fork lever is adapted to be resiliently urged to the fuel increasing side by a starting spring.
Since the aforementioned double-lever type governor device is capable of moving the control rack to a starting fuel increasing position by the starting spring through the fork lever, advantageously the engine can be readily started. There is, however, such a problem associated therewith, as black smoke is generated at the time of a quick acceleration of the engine.
That is, when an acceleration lever and the like are quickly operated for a quick acceleration, the tension force of the governor spring is promptly increased. But, since there exists a time lag in an increase of the engine revolution speed, a balance between the governor force and the tension force of the spring is broken and then the spring lever and the fork lever are quickly swung to the fuel increasing side. Since the swing is quick, the fork lever is further swung to the fuel increasing side by both its inertial force and the tension force of the starting spring and to make the control rack overrun to the starting fuel increasing position even after the spring lever has been received by the fuel limiting pin. Thereby, a fuel injection quantity of the fuel injection pump becomes excessive to generate black smoke.
Further, the problem of the smoke generated at the quick accelerating operation was caused also in a single-lever type governor device of a diesel engine with a turbocharger.
That is, similarly to the above, the tension force of the governor spring is promptly increased by the quick accelerating operation of the acceleration lever and the like. But, there exists a time lag in the increase of the engine revolution speed as well as there also exists a time lag in an increase of a boost pressure of the turbocharger. Therefore, an excessive fuel is supplied relative to a less intake air to generate black smoke.